Tonight I did a presentation at a Unity3d user group.
I referenced a few items in the discussion that I thought might be helpful to have direct links to.

Basic Shader
http://docs.unity3d.com/Manual/SL-VertexFragmentShaderExamples.html#simpleshader

Creating Shaders – Surface Shaders, but have a lot of solid basics
http://unitygems.com/noobshader1/#prettyPhoto

Unity Sample Assets
http://blogs.unity3d.com/2014/01/17/new-sample-assets-beta/

Final Shader (with a few tweaks beyond the presentation version)
http://dwulf.com/source/Fudge%20Ripple.shader